In current vehicle designs, which includes both automobiles and trucks, the use of LEDs is preferred for illuminating tail-lamps and turn-signal lamps rather than conventional filament lamps. LEDs require a small mounting area, are bright, have a high reliability and a relatively long useful life.
A problem that arises in directly replacing the filament lamps with LEDs is that automobiles and most trucks utilize a 12-volt battery and many tractor trailer trucks utilize a 24-volt battery. Since LEDs operate on a d-c voltage ranging from 3.5 to 4.5 volts d-c the high-voltage filament lamps cannot be directly replaced by the low-voltage LEDs. To solve this problem the prior art attaches a voltage-dropping resistive element in series with the LEDs and the vehicle battery. This solution allows the resistive element to lower the d-c voltage from the vehicle battery to a level that is required to operate the LEDs. However, the resistive element is relatively large, is cumbersome and produces a substantial amount of heat that may cause vehicle elements surrounding the resistive element to be affected.
The inventive d-c to d-c converter circuit (DDCC) utilizes a passive electronic circuit to lower the voltage and the current to an acceptable level to operate the LEDs, and eliminates the voltage dropping resistive element and the heat it generates. Additionally, the DDCC is much smaller than the resistive element which makes it easy to incorporate into the vehicle electrical wiring cable that is connected from the vehicle battery to the vehicle tail lamps. In addition, the DDCC is universal in that it is self adjusting to the types and quantity of LED's used, as long as the total wattage drawn does not exceed the wattage level of the LEDs.
A search of the prior art did not disclose any U.S patents or industry literature that read on the claims of the instant invention.